CN102932305A - Code element synchronizer and code element synchronization method - Google Patents

Abstract

The invention discloses a code element synchronizer and a code element synchronization method. The code element synchronizer comprises a sampling and quantizing unit, a lead code synchronization unit, a frame synchronization code synchronization unit and a timer. The code element synchronization method comprises the following steps that: (S1) the sampling and quantizing unit samples and quantizes baseband signal waveforms; (S3) the lead code synchronization unit carries out normalization and filtered wave matching on the sampled and quantized baseband signal waveforms according to lead code waveforms in a dPMR (digital Private Mobile Ratio) standard frame structure, and outputs results to the sampling and quantizing unit; and (S5) the frame synchronization code synchronization unit carries out normalization and filtered wave matching on the sampled and quantized baseband signal waveforms according to frame synchronization code waveforms in the dPMR standard frame structure, and outputs results to the sampling and quantizing unit. According to the code element synchronizer and the code element synchronization method, the locations of lead code and frame synchronization code waveforms in the input baseband signal waveforms can be accurately located, and the sampling decision point of the sampling and quantizing unit is adjusted at the beginning of communication and during the communication.

Description

A kind of symbol synchronization device and symbol synchronization method

Technical field

The present invention relates to the symbol synchronization technology, more particularly, relate to a kind of symbol synchronization device and the symbol synchronization method that are applicable in the dPMR standard demodulation.

Background technology

DPMR(Digital Private Mobile Radio) system, intermediate frequency Modulation adopts frequency division multiple access (FDMA) technology, and each radio-frequency carrier bandwidth is 6.25kHz.Fig. 1 is the protocol stack block diagram of dPMR standard, as shown in Figure 1, whole dPMR standard is divided into control plane and user plane, have 3 layers of air interface (Air Interface is called for short AI) structure, be respectively from the bottom up: physical layer (Physical Layer, be called for short PL), data link layer (Data Link Layer is called for short DDL) and call control layer (Call Control Layer is called for short CCL).Other external equipment just can access this standard of connection as long as support these three layers of air interface specification.

Fig. 2 is the frame structure schematic diagram of dPMR standard, and as shown in Figure 2, the frame structure of a complete voice call is comprised of a frame (Head), super frame (sf) and tail frame (End), wherein, has lead code and frame swynchronization code in the fixed sequence program of a frame and superframe.Press the dPMR standard code, lead code is 72bits:5F 5F 5F 5F 5F 5F 5F 5F 5F, and frame swynchronization code is 24bits:5F F7 7D.In same frame, the time interval between lead code and the frame swynchronization code that is adjacent is 80ms, and the time interval between two frame swynchronization codes is 160ms.

The effect of lead code namely is to carry out symbol synchronization in the baseband signal of dPMR standard, one section preamble sequence is arranged: 5F 5F 5F 5F 5F 5F 5F 5F 5F during the communication beginning, (lead code was advanced the portion waveshape after the 4FSK modulation to desirable lead code waveform, every dotted line is 1 symbol numbers) as shown in Figure 3, each crest value of lead code is identical.The conventional method of lead code waveform is to seek the identical waveform of this adjacent wave peak value in the baseband signal waveform of existing detection input, this method realizes simple, but can produce two problems, the one, when noise jamming is arranged, each crest value just might be not identical, wants the position of lead code waveform in the baseband signal waveform of accurately location input very difficult; The 2nd, in a complete communication process, lead code only occurs when the communication beginning, only carrying out synchronous method for lead code can only be when communication begins, try to achieve the optimal sampling determination point, again the optimal sampling determination point is not adjusted in the communication process of back, along with the increase of call duration time, the error of optimal sampling determination point accumulative total is increasing, thereby causes the code element step-out.

Summary of the invention

The accuracy that the present invention is directed to the position of lead code waveform in the baseband signal waveform of inputting existing symbol synchronization scheme location is not high, and the defective that can't in communication process, adjust the optimum sampling determination point, the position of lead code waveform in a kind of baseband signal waveform that can accurately locate input is provided, and can be in the communication beginning and symbol synchronization device and the symbol synchronization method in by process the optimum sampling determination point adjusted.

The technological means that the present invention solves its technical problem to be provided is: a kind of symbol synchronization device is provided, comprises:

The sample quantization unit carries out sample quantization according to local reference clock to baseband signal waveform, and the sample quantization value of output baseband signal waveform;

The lead code lock unit, carry out normalization and matched filtering according to the baseband signal waveform of the lead code waveform in the dPMR standard frame after to sample quantization, and obtain the phase place of maximum amplitude in the baseband signal waveform after normalization and matched filtering, the phase place of the maximum amplitude that obtains is exported described sample quantization unit to adjust the sampling determination point of described sample quantization unit;

The frame swynchronization code lock unit, carry out normalization and matched filtering according to the baseband signal waveform of the frame swynchronization code waveform in the dPMR standard frame after to sample quantization, and obtain the phase place of maximum amplitude in the baseband signal waveform after normalization and matched filtering, the phase place of the maximum amplitude that obtains is exported described sample quantization unit to adjust the sampling determination point of described sample quantization unit;

Timer, when beginning communication enables described lead code lock unit until it stops to enable after exporting the phase place of maximum amplitude in its baseband signal waveform of obtaining, and enable described frame swynchronization code lock unit until it stops to enable after exporting the phase place of maximum amplitude in its baseband signal waveform of obtaining through 60 milliseconds, and whenever again enable described frame swynchronization code lock unit until it stops to enable after exporting the phase place of maximum amplitude in its baseband signal waveform of obtaining through 120 milliseconds.

Symbol synchronization device of the present invention, described lead code lock unit comprises:

Lead code normalization filter unit carries out normalization filtering according to the amplitude of the amplitude of the lead code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of described sample quantization unit output;

Lead code matched filtering unit, receive through the filtered baseband signal waveform of normalization, the lead code waveform of choosing 1/3rd in the dPMR standard frame carries out three matched filterings to the filtered baseband signal waveform of described normalization, and exports the phase place of maximum amplitude in the baseband signal waveform that searches after each matched filtering;

Judging unit, receive three phase places of described lead code matched filtering unit output and judge whether described three phase places equate, if equal then this phase place is exported described sample quantization unit to adjust the sampling determination point of described sample quantization unit, if unequal described three phase places that receive that then abandon.

Preferably, described lead code normalization filter unit carries out normalization filtering according to the amplitude of the baseband signal waveform of following formula after to sample quantization:

unify ₁(i)＝sample(i)×α ₁;0≤i＜num_ref ₁

α ₁＝max(|ref ₁(i)|)/max(|sample(i)|);0≤i＜num_ref ₁

Wherein, unify ₁(i) the sample quantization value of the filtered baseband signal waveform of expression normalization, the sample quantization value of the baseband signal of sample (i) expression sample quantization unit 110 outputs, α ₁The normalization coefficient of expression lead code, ref ₁(i) be the value of symbol of lead code waveform in the dPMR standard frame, max (| ref ₁(i) |) be the amplitude maximum of lead code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num_ref ₁Symbol numbers for lead code waveform in the dPMR standard frame;

Described lead code matched filtering unit carries out matched filtering according to following formula to the baseband signal waveform after normalization:

${\mathrm{match}}_1\left(i\right)=\underset{i=\mathrm{num}\_{\mathrm{<figure-callout\; id="1"\; label="ref"\; filenames="HDA00001985451400021.png,HDA00001985451400031.png"\; state="\{\{state\}\}">ref</figure-callout>}}_1}{\overset{{\mathrm{NUM}}_1-1}{\mathrm{\&Sigma;}}}\underset{j=0}{\overset{\mathrm{num}\_{\mathrm{ref}}_1-1}{\mathrm{\&Sigma;}}}{\mathrm{unify}}_1(i-j)\&CenterDot;{\mathrm{ref}}_1(\mathrm{num}\_{\mathrm{ref}}_1-j)$

Wherein, match ₁(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₁=N * M ₁, M ₁The symbol numbers of 1/3rd lead code wave sequence in the expression dPMR standard frame, N is the symbol numbers of each symbol clock in the cycle of sampling to baseband signal waveform in described sample quantization unit.

Symbol synchronization device of the present invention, described frame swynchronization code lock unit comprises:

Frame swynchronization code normalization filter unit carries out normalization filtering according to the amplitude of the amplitude of the frame swynchronization code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of described sample quantization unit output;

Frame swynchronization code matched filtering unit, receive through the filtered baseband signal waveform of normalization, according to the frame swynchronization code waveform in the dPMR standard frame the filtered baseband signal waveform of described normalization is carried out matched filtering, and obtain the phase place of maximum amplitude in the baseband signal waveform, the described phase place of obtaining is exported described sample quantization unit to adjust the sampling determination point of described sample quantization unit.

Preferably, described frame swynchronization code normalization filter unit carries out normalization filtering according to the amplitude of the baseband signal waveform of following formula after to sample quantization:

unify ₂(i)＝sample(i)×α ₂;0≤i＜num_ref ₂

α ₂＝max(|ref ₂(i)|)/max(|sample(i)|);0≤i＜num_ref ₂

Wherein, unify ₂(i) the sample quantization value of the filtered baseband signal waveform of expression normalization, the sample quantization value of the baseband signal of sample (i) expression described sample quantization unit (110) output, α ₂The normalization coefficient of expression frame swynchronization code, ref ₂(i) be the value of symbol of frame swynchronization code waveform in the dPMR standard frame, max (| ref ₂(i) |) be the amplitude maximum of frame swynchronization code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num ref ₂Symbol numbers for frame swynchronization code waveform in the dPMR standard frame;

Described frame swynchronization code matched filtering unit carries out matched filtering according to following formula to the baseband signal waveform after normalization:

${\mathrm{match}}_2\left(i\right)=\underset{i=\mathrm{num}\_{\mathrm{<figure-callout\; id="2"\; label="ref"\; filenames="HDA00001985451400021.png,HDA00001985451400031.png"\; state="\{\{state\}\}">ref</figure-callout>}}_2}{\overset{{\mathrm{NUM}}_2-1}{\mathrm{\&Sigma;}}}\underset{j=0}{\overset{\mathrm{num}\_{\mathrm{ref}}_2-1}{\mathrm{\&Sigma;}}}{\mathrm{unify}}_2(i-j)\&CenterDot;{\mathrm{ref}}_2(\mathrm{num}\_{\mathrm{ref}}_2-j)$

Wherein, match ₂(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₂=N * M ₂, M ₂The symbol numbers of the frame swynchronization code wave sequence in the expression dPMR standard frame, N is the symbol numbers of each symbol clock in the cycle of sampling to baseband signal waveform in described sample quantization unit.

A kind of symbol synchronization method is provided, may further comprise the steps:

S1, sample quantization unit carry out sample quantization according to local reference clock to baseband signal waveform;

S2, timer enable the lead code lock unit;

S3, described lead code lock unit carry out normalization and matched filtering according to the baseband signal waveform of the lead code waveform in the dPMR standard frame after to sample quantization, and obtain the phase place of maximum amplitude in the baseband signal waveform after normalization and matched filtering, the phase place of the maximum amplitude that obtains is exported described sample quantization unit to adjust the sampling determination point of described sample quantization unit;

S4, described timer stop to enable described lead code lock unit, and enable the frame swynchronization code lock unit through 60 milliseconds;

S5, described frame swynchronization code lock unit carry out normalization and matched filtering according to the baseband signal waveform of the frame swynchronization code waveform in the dPMR standard frame after to sample quantization, and obtain the phase place of maximum amplitude in the baseband signal waveform after normalization and matched filtering, the phase place of the maximum amplitude that obtains is exported described sample quantization unit to adjust the sampling determination point of described sample quantization unit;

S6, described timer stop to enable described frame swynchronization code lock unit, and again enable described frame swynchronization code lock unit, execution in step S5 through 120 milliseconds.

Symbol synchronization method of the present invention, described lead code lock unit comprises lead code normalization filter unit, lead code matched filtering unit and judging unit, described step S3 may further comprise the steps:

S31, described lead code normalization filter unit carry out normalization filtering according to the amplitude of the amplitude of the lead code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of described sample quantization unit output;

S32, described lead code matched filtering unit receive through the filtered baseband signal waveform of normalization, the lead code waveform of choosing 1/3rd in the dPMR standard frame carries out three matched filterings to the filtered baseband signal waveform of described normalization, and exports the phase place of maximum amplitude in the baseband signal waveform that searches after each matched filtering;

S33, described judging unit receive three phase places of described lead code matched filtering unit output and judge whether described three phase places equate, if equate then execution in step S34, unequal then execution in step S31;

S34, described judging unit are exported described sample quantization unit to adjust the sampling determination point of described sample quantization unit with the phase place of maximum amplitude in the baseband signal waveform.

Preferably, described lead code normalization filter unit carries out normalization filtering according to the amplitude of the baseband signal waveform of following formula after to sample quantization:

unify ₁(i)＝sample(i)×α ₁;0≤i＜num_ref ₁

α ₁＝max(|ref ₁(i)|)/max(|sample(i)|);0≤i＜num_ref ₁

Wherein, the sample quantization value of the filtered baseband signal waveform of unify (i) expression normalization, the sample quantization value of the baseband signal of sample (i) expression sample quantization unit 110 outputs, α ₁The normalization coefficient of expression lead code, ref ₁(i) be the value of symbol of lead code waveform in the dPMR standard frame, max (| ref ₁(i) |) be the amplitude maximum of lead code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num_ref ₁Symbol numbers for lead code waveform in the dPMR standard frame;

Described lead code matched filtering unit carries out matched filtering according to following formula to the baseband signal waveform after normalization:

${\mathrm{match}}_1\left(i\right)=\underset{i=\mathrm{num}\_{\mathrm{<figure-callout\; id="1"\; label="ref"\; filenames="HDA00001985451400021.png,HDA00001985451400031.png"\; state="\{\{state\}\}">ref</figure-callout>}}_1}{\overset{{\mathrm{NUM}}_1-1}{\mathrm{\&Sigma;}}}\underset{j=0}{\overset{\mathrm{num}\_{\mathrm{ref}}_1-1}{\mathrm{\&Sigma;}}}{\mathrm{unify}}_1(i-j)\&CenterDot;{\mathrm{ref}}_1(\mathrm{num}\_{\mathrm{ref}}_1-j)$

Wherein, match ₁(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₁=N * M ₁, M ₁The symbol numbers of 1/3rd lead code wave sequence in the expression dPMR standard frame, N is the symbol numbers of each symbol clock in the cycle of sampling to baseband signal waveform in described sample quantization unit.

Symbol synchronization method of the present invention, described frame swynchronization code lock unit comprise frame swynchronization code normalization filter unit and frame swynchronization code matched filtering unit, and described step S5 comprises step:

S51, described frame swynchronization code normalization filter unit carry out normalization filtering according to the amplitude of the amplitude of the frame swynchronization code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of described sample quantization unit output;

S52, described frame swynchronization code matched filtering unit receive through the filtered baseband signal waveform of normalization, according to the frame swynchronization code waveform in the dPMR standard frame the filtered baseband signal waveform of described normalization is carried out matched filtering, and obtain the phase place of maximum amplitude in the baseband signal waveform, the described phase place of obtaining is exported described sample quantization unit to adjust the sampling determination point of described sample quantization unit.

Preferably, described frame swynchronization code normalization filter unit carries out normalization filtering according to the amplitude of the baseband signal waveform of following formula after to sample quantization:

unify ₂(i)＝sample(i)×α ₂;0≤i＜num_ref ₂

α ₂＝max(|ref ₂(i)|)/max(|sample(i)|);0≤i＜num_ref ₂

Wherein, unify ₂(i) the sample quantization value of the filtered baseband signal waveform of expression normalization, the sample quantization value of the baseband signal of sample (i) expression described sample quantization unit (110) output, α ₂The normalization coefficient of expression frame swynchronization code, ref ₂(i) be the value of symbol of frame swynchronization code waveform in the dPMR standard frame, max (| ref ₂(i) |) be the amplitude maximum of frame swynchronization code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num_ref ₂Symbol numbers for frame swynchronization code waveform in the dPMR standard frame;

Described frame swynchronization code matched filtering unit carries out matched filtering according to following formula to the baseband signal waveform after normalization:

${\mathrm{match}}_2\left(i\right)=\underset{i=\mathrm{num}\_{\mathrm{<figure-callout\; id="2"\; label="ref"\; filenames="HDA00001985451400021.png,HDA00001985451400031.png"\; state="\{\{state\}\}">ref</figure-callout>}}_2}{\overset{{\mathrm{NUM}}_2-1}{\mathrm{\&Sigma;}}}\underset{j=0}{\overset{\mathrm{num}\_{\mathrm{ref}}_2-1}{\mathrm{\&Sigma;}}}{\mathrm{unify}}_2(i-j)\&CenterDot;{\mathrm{ref}}_2(\mathrm{num}\_{\mathrm{ref}}_2-j)$

Wherein, match ₂(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₂=N * M ₂, M ₂The symbol numbers of the frame swynchronization code wave sequence in the expression dPMR standard frame, N is the symbol numbers of each symbol clock in the cycle of sampling to baseband signal waveform in described sample quantization unit.

Symbol synchronization utensil of the present invention has following beneficial effect: carry out normalization and matched filtering based on the baseband signal waveform of the lead code waveform in the dPMR standard frame after to sample quantization, phase place with maximum amplitude in the baseband signal waveform after normalization and matched filtering is exported the sample quantization unit to adjust the sampling determination point of sample quantization unit as the optimum sampling determination point, has realized the accurate location to the position of lead code waveform in the baseband signal waveform of input; And, in communication process, carry out normalization and matched filtering based on the baseband signal waveform of the frame swynchronization code waveform in the dPMR standard frame after to sample quantization, with the phase place of maximum amplitude in the baseband signal waveform after normalization and matched filtering as optimum sampling determination point output sample quantization unit to adjust the sampling determination point of sample quantization unit, realized in communication process the adjustment to the sampling determination point; In addition, timer stops respectively they enable reduced power consumption after the phase place of lead code lock unit and frame swynchronization code lock unit output maximum amplitude.

Symbol synchronization method of the present invention has the beneficial effect identical with symbol synchronization device of the present invention, does not repeat them here.

Description of drawings

Fig. 1 is the protocol stack block diagram of dPMR standard;

Fig. 2 is the frame structure schematic diagram of dPMR standard;

Fig. 3 is desirable lead code oscillogram;

Fig. 4 is the structured flowchart of the first embodiment of symbol synchronization device 100 of the present invention;

Fig. 5 is the baseband signal waveform figure that the sample quantization unit sampling quantizes;

Fig. 6 is through the filtered baseband signal waveform figure of lead code lock unit normalization;

Fig. 7 is the baseband signal waveform figure after the normalization of lead code lock unit and matched filtering;

Fig. 8 is through the filtered baseband signal waveform figure of frame swynchronization code lock unit normalization;

Fig. 9 is the baseband signal waveform figure after the normalization of frame swynchronization code lock unit and matched filtering;

Figure 10 is the structured flowchart of symbol synchronization device 100 second embodiment of the present invention;

Figure 11 is the working state figure of symbol synchronization device of the present invention;

Figure 12 is the method flow diagram of symbol synchronization method the first embodiment of the present invention;

Figure 13 is the frame swynchronization code lock unit of the present invention optimum sampling determination point that obtains and the position corresponding relation figure that treats frame swynchronization code waveform in the synchronous baseband signal waveform.

Embodiment

Below in conjunction with drawings and Examples the present invention will be further explained explanation.

The present invention is that design and realization are applicable to the symbol synchronization device in the dPMR standard demodulation.The symbol synchronization device is important component part in the demodulation of radio communication.Receive signal (baseband signal) through behind the intermediate frequency demodulation, extract synchronised clock by the symbol synchronization device, seek optimal judgement constantly, thereby recover baseband signal.

The present invention at first carries out sample quantization according to the local reference clock of receiving terminal to the baseband signal waveform of input; Because symbol synchronization of the present invention is based on the matched filtering principle, the wave-shape amplitude of coupling needs unified, so the baseband signal after process quantizes is carried out amplitude normalization by the reference waveform of normalization filtering and coupling, then carry out matched filtering with reference waveform, the reference waveform that the present invention chooses is distinctive lead code and frame swynchronization code waveform in the dPMR standard frame; In the result of normalization and matched filtering, seek out the phase place with maximum amplitude, send into the sample quantization unit as optimum sampling judging point (the symbol synchronization clock that namely recovers), to adjust the sampling determination point of sample quantization unit, namely adjust the sampling judgement of local reference clock constantly, thereby correctly recovered the baseband signal of transmitting terminal.

Fig. 4 is the structured flowchart of the first embodiment of symbol synchronization device 100 of the present invention, and as shown in Figure 4, in the present embodiment, symbol synchronization device 100 comprises sample quantization unit 110, lead code lock unit 120, frame swynchronization code lock unit 130 and timer 140.

Sample quantization unit 110 carries out sample quantization according to local reference clock to baseband signal waveform, and the sample quantization value of output baseband signal waveform.Sample quantization unit 110 N the symbol of in each symbol clock cycle T, sampling, sample frequency f'=N/T '.T'=T+ σ wherein, T represents the transmitting terminal symbol clock cycle, and T' represents local reference clock cycle, and σ represents the error of local reference clock and transmitting terminal clock, and this error amount is because in asynchronous communication, the Crystal Oscillator Errors of transmitter and receiver causes.

The 4FSK modulation of the continuous phase of 4.8k/s is adopted in the dPMR standard code, and described symbol refers to the modulation symbol of 4FSK.The frequency error of the clock maximum that symbol synchronization device 100 of the present invention allows as shown in the formula:

$\mathrm{\&Delta;}{f}_P=\frac{\&PlusMinus;1}{4.8\mathrm{kHz}\&times;N\&times;160\mathrm{ms}}\&times;{10}^6=\&PlusMinus;1302/N\left(\mathrm{ppm}\right)$

And the frequency error of existing common crystals: Δ f＜＜± 50 (ppm) therefore when the number N of symbol is set, make it possible to satisfy the performance of most of crystal oscillators.For example, when N=16 was set, the frequency error of the clock maximum that symbol synchronization device 100 allows was f _PThe performance of most of crystal oscillators can be satisfied in=± 1302/N=± 81.375 (ppm).Sample quantization unit 110 16 symbols of in each symbol clock cycle T, sampling, sample frequency f'=16/T' carries out modulation /demodulation according to the dPMR standard, and the baseband signal waveform sample behind the sample quantization (i) is as shown in Figure 5.

In the present embodiment, the baseband signal behind the 110 pairs of sample quantizations in sample quantization unit is stored, and stores respectively continuous num_ref ₁Individual sample quantization value and continuous num_ref ₂Individual sample quantization value, num_ref ₁Be the symbol numbers of lead code waveform in the dPMR standard frame, num_ref ₂Symbol numbers for frame swynchronization code waveform in the dPMR standard frame.Therefore, symbol synchronization device 100 of the present invention can also comprise the memory that is internal or external at sample quantization unit 110.

Lead code lock unit 120 as reference waveform (as shown in Figure 3), when being timed device 140 and enabling, (is the continuous num_ref of sample quantization unit 110 storages to the baseband signal waveform behind the sample quantization with the lead code waveform in the dPMR standard frame ₁Individual sample quantization value) carries out normalization and matched filtering, and obtain the phase place that has maximum amplitude in the baseband signal waveform after normalization and matched filtering, with the phase place output sample quantization unit 110 with maximum amplitude that obtains to adjust the sampling determination points of sample quantization unit 110.The phase place with maximum amplitude that lead code lock unit 120 obtains is the optimum sampling determination point, and the corresponding moment is the optimal sampling judgement moment.

In the present embodiment, lead code lock unit 120 carries out normalization filtering according to the baseband signal waveform of following formula after to sample quantization:

unify ₁(i)＝sample(i)×α ₁;0≤i＜num_ref ₁

α ₁＝max(|ref ₁(i)|)/max(|sample(i)|);0≤i＜num_ref ₁

Wherein, unify ₁(i) the sample quantization value of the filtered baseband signal waveform of expression normalization, the sample quantization value of the baseband signal of sample (i) expression sample quantization unit 110 outputs, α ₁The normalization coefficient of expression lead code, ref ₁(i) be the value of symbol of lead code waveform in the dPMR standard frame, max (| ref ₁(i) |) be the amplitude maximum of lead code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num_ref ₁Symbol numbers for lead code waveform in the dPMR standard frame.Because the lead code waveform as the reference waveform is fixed waveform, so its amplitude maximum max (| ref ₁(i) |) be a constant C ₁, its symbol numbers num_ref ₁It also is a constant C 2.Through the filtered baseband signal waveform of lead code lock unit 120 normalization as shown in Figure 6.

In the present embodiment, lead code lock unit 120 carries out matched filtering according to following formula to the filtered baseband signal waveform of normalization:

${\mathrm{match}}_1\left(i\right)=\underset{i=\mathrm{num}\_{\mathrm{<figure-callout\; id="1"\; label="ref"\; filenames="HDA00001985451400021.png,HDA00001985451400031.png"\; state="\{\{state\}\}">ref</figure-callout>}}_1}{\overset{{\mathrm{NUM}}_1-1}{\mathrm{\&Sigma;}}}\underset{j=0}{\overset{\mathrm{num}\_{\mathrm{ref}}_1-1}{\mathrm{\&Sigma;}}}{\mathrm{unify}}_1(i-j)\&CenterDot;{\mathrm{ref}}_1(\mathrm{num}\_{\mathrm{ref}}_1-j)$

Wherein, match ₁(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₁=N * M ₁, M ₁The symbol numbers of 1/3rd lead code wave sequence in the expression dPMR standard frame.Through the baseband signal waveform after lead code lock unit 120 normalization and the matched filtering as shown in Figure 7.

Frame swynchronization code lock unit 130 (can read the continuous num_ref of sample quantization unit 110 storages according to the baseband signal waveform of the frame swynchronization code waveform in the dPMR standard frame after to sample quantization ₂Individual sample quantization value) carries out normalization and matched filtering, and obtain the phase place that has maximum amplitude in the baseband signal waveform after normalization and matched filtering, with the phase place output sample quantization unit 110 of the maximum amplitude that obtains to adjust the sampling determination points of sample quantization unit 110.

In the present embodiment, frame swynchronization code lock unit 130 carries out normalization filtering according to the amplitude of the baseband signal waveform of following formula after to sample quantization:

unify ₂(i)＝sample(i)×α ₂;0≤i＜num_ref ₂

α ₂＝max(|ref ₂(i)|)/max(|sample(i)|);0≤i＜num_ref ₂

Wherein, unify ₂(i) the sample quantization value of the filtered baseband signal waveform of expression normalization, the sample quantization value of the baseband signal of sample (i) expression described sample quantization unit (110) output, α ₂The normalization coefficient of expression frame swynchronization code, ref ₂(i) be the value of symbol of frame swynchronization code waveform in the dPMR standard frame, max (| ref ₂(i) |) be the amplitude maximum of frame swynchronization code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num_ref ₂Symbol numbers for frame swynchronization code waveform in the dPMR standard frame.Through the baseband signal waveform after 120 normalization of frame swynchronization code lock unit as shown in Figure 8.

In the present embodiment, frame swynchronization code lock unit 130 carries out matched filtering according to following formula to the baseband signal waveform after normalization:

${\mathrm{match}}_2\left(i\right)=\underset{i=\mathrm{num}\_{\mathrm{<figure-callout\; id="2"\; label="ref"\; filenames="HDA00001985451400021.png,HDA00001985451400031.png"\; state="\{\{state\}\}">ref</figure-callout>}}_2}{\overset{{\mathrm{NUM}}_2-1}{\mathrm{\&Sigma;}}}\underset{j=0}{\overset{\mathrm{num}\_{\mathrm{ref}}_2-1}{\mathrm{\&Sigma;}}}{\mathrm{unify}}_2(i-j)\&CenterDot;{\mathrm{ref}}_2(\mathrm{num}\_{\mathrm{ref}}_2-j)$

Wherein, match ₂(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₂=N * M ₂, M ₂The symbol numbers of the frame swynchronization code wave sequence in the expression dPMR standard frame.Through the baseband signal waveform after frame swynchronization code lock unit 130 normalization and the matched filtering as shown in Figure 9.

When the communication beginning, external equipment enables code element synchronizer 100, and at this moment, timer 140 enables lead code lock unit 120 until stop to enable after the phase place of maximum amplitude in lead code lock unit 120 its baseband signal waveform of obtaining of output; And after 60 milliseconds, enable frame swynchronization code lock unit 130 until stop to enable after the phase place of maximum amplitude in frame swynchronization code lock unit 130 its baseband signal waveform of obtaining of output; From shown in Figure 2, in the frame structure of dPMR standard, have 5 frame swynchronization codes, timer 140 is every to enable frame swynchronization code lock unit 130 until stop to enable after the phase place of maximum amplitude in frame swynchronization code lock unit 130 its baseband signal waveform of obtaining of output again through 120 milliseconds, be the tail frame after 5 frame swynchronization codes, represent this sign off, external equipment stops to enable code element synchronizer 100.During next time communication beginning, external equipment enables code element synchronizer 100 again, and timer 140 will repeat above-mentioned work.

In the present embodiment, the reference coupling waveform that uses has two: the lead code waveform in the dPMR standard frame and frame swynchronization code waveform, wherein, the lead code waveform is 72bits altogether, the frame swynchronization code waveform is 24bits altogether, mate to mate for 1 time and finish frame swynchronization code, mate to mate for 3 times and finish lead code, because the dPMR regulation adopts the 4FSK modulation, 2bits shines upon 1 sign bit, and is as shown in table 1, so 1/3rd lead code wave sequence and whole frame swynchronization code waveform are 24bits, be mapped as 12 symbol numbers, i.e. M ₁And M ₂All be 12.

The mapping of table 14FSK modulation symbol

Figure 10 is the structured flowchart of symbol synchronization device 100 second embodiment of the present invention, and as shown in figure 10, in the present embodiment, lead code lock unit 120 comprises:

Lead code normalization filter unit 121, its amplitude according to the amplitude of the lead code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of sample quantization unit 110 outputs is carried out normalization filtering;

Lead code matched filtering unit 122, it receives through the filtered baseband signal waveform of normalization, the lead code waveform of choosing 1/3rd in the dPMR standard frame carries out three matched filterings to the filtered baseband signal waveform of described normalization, and exports the phase place of maximum amplitude in the baseband signal waveform that searches after each matched filtering;

Judging unit 123, it receives the phase place of three maximum amplitudes of lead code matched filtering unit 122 outputs, judge whether these three phase places equate, if equal with this phase place output sample quantization unit 110 to adjust the sampling determination points of sample quantization unit 110, if unequal three phase places that receive that then abandon.

If three phase places that judging unit 123 receives from lead code matched filtering unit 122 are unequal, this three phase places have been abandoned, because the phase place that lead code lock unit 120 does not have output to have maximum amplitude arrives sample quantization unit 110, timer 140 continues to enable sample quantifying unit 110 to have the phase place of maximum amplitude until lead code lock unit 120 is successfully exported.

In the present embodiment, frame swynchronization code lock unit 130 comprises:

Frame swynchronization code normalization filter unit 131, its amplitude according to the amplitude of the frame swynchronization code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of sample quantization unit 110 outputs is carried out normalization filtering;

Frame swynchronization code matched filtering unit 132, it receives through the filtered baseband signal waveform of normalization, according to the frame swynchronization code waveform in the dPMR standard frame the filtered baseband signal waveform of normalization is carried out matched filtering, and obtain the phase place of maximum amplitude in the baseband signal waveform, with the described phase place output sample quantization unit 110 that obtains to adjust the sampling determination points of sample quantization unit 110.

In the present embodiment, the operating state of symbol synchronization device 100 as shown in figure 11, when lead code lock unit 120 was timed device 140 and enables, symbol synchronization device 100 was operated in lead code search attitude; When frame swynchronization code lock unit 130 was timed device 140 and enables, symbol synchronization device 100 was operated in frame swynchronization code search attitude.If three phase matched results that judging unit 123 receives from lead code matched filtering unit 122 are consistent, timer 140 just stops to enable lead code lock unit 120, and the beginning timing, wait the full 60ms(Idle state 1 of timing), timer 140 enables frame swynchronization code lock unit 130; If three phase matched results are inconsistent, timer 140 continues to enable lead code lock unit 120 until three phase matched results stop to enable after consistent.Timer 140 enables frame swynchronization code lock unit 130 until frame swynchronization code lock unit 130 stops to enable after finishing the coupling of frame swynchronization code, and timer 140 beginning timing wait the full 120ms(Idle state 2 of timing) after again enable frame swynchronization code lock unit 130.In once communicating by letter, timer 140 enables the frame swynchronization code lock unit 130 5 times altogether.

In the present embodiment, not identical not the repeating them here of the first embodiment of all the other situations and symbol synchronization device 100 of the present invention.

The present invention also provides a kind of symbol synchronization method, and Figure 12 is the method flow diagram of symbol synchronization method the first embodiment of the present invention, as shown in figure 12, said method comprising the steps of:

When the communication beginning, external equipment enables code element synchronizer 100, enter step S1, sample quantization unit 110 carries out sample quantization according to local reference clock to baseband signal waveform, baseband signal behind the 110 pairs of sample quantizations in sample quantization unit is stored, and stores respectively the continuous num_ref before each current time ₁Individual sample quantization value and continuous num_ref ₂Individual sample quantization value, num_ref ₁Be the symbol numbers of lead code waveform in the dPMR standard frame, num_ref ₂Symbol numbers for frame swynchronization code waveform in the dPMR standard frame;

S2, timer 140 enable lead code lock unit 120;

S3, lead code lock unit 120 carry out normalization and matched filtering according to the baseband signal waveform of the lead code waveform in the dPMR standard frame after to sample quantization, and obtain the phase place that has maximum amplitude in the baseband signal waveform after normalization and matched filtering, with the phase place with maximum amplitude obtained as optimum sampling determination point (the symbol synchronization clock that namely recovers) output sample quantization unit 110 to adjust the sampling determination points of sample quantization unit 110;

S4, timer 140 stop to enable lead code lock unit 120, and enable frame swynchronization code lock unit 130 through 60 milliseconds;

S5, frame swynchronization code lock unit 130 carry out normalization and matched filtering according to the baseband signal waveform of the frame swynchronization code waveform in the dPMR standard frame after to sample quantization, and obtain the phase place that has maximum amplitude in the baseband signal waveform after normalization and matched filtering, with the phase place with maximum amplitude obtained as optimal judgement point (the symbol synchronization clock that namely in communication process, recovers) output sample quantization unit 110 to adjust the sampling determination points of sample quantization unit 110;

S6, timer 140 stop to enable frame swynchronization code lock unit 130, and again enable frame swynchronization code lock unit 130, execution in step S5 through 120 milliseconds.

Behind sign off, external equipment stops to enable code element synchronizer 100, and in communication process, timer 140 is for enabling the frame swynchronization code lock unit 130 5 times.

In the present embodiment, lead code lock unit 120 carries out normalization filtering according to the baseband signal waveform of following formula after to sample quantization:

unify ₁(i)＝sample(i)×α ₁;0≤i＜num_ref ₁

α ₁＝max(|ref ₁(i)|)/max(|sample(i)|);0≤i＜num_ref ₁

Wherein, unify ₁(i) the sample quantization value of the filtered baseband signal waveform of expression normalization, the sample quantization value of the baseband signal of sample (i) expression sample quantization unit 110 outputs, α ₁The normalization coefficient of expression lead code, ref ₁(i) be the value of symbol of lead code waveform in the dPMR standard frame, max (| ref ₁(i) |) be the amplitude maximum of lead code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num_ref ₁Symbol numbers for lead code waveform in the dPMR standard frame.Because the lead code waveform as the reference waveform is fixed waveform, so its amplitude maximum max (| ref ₁(i) |) be a constant C ₁, its symbol numbers num_ref ₁It also is a constant C 2.

In the present embodiment, lead code lock unit 120 carries out matched filtering according to following formula to the filtered baseband signal waveform of normalization:

${\mathrm{match}}_1\left(i\right)=\underset{i=\mathrm{num}\_{\mathrm{<figure-callout\; id="1"\; label="ref"\; filenames="HDA00001985451400021.png,HDA00001985451400031.png"\; state="\{\{state\}\}">ref</figure-callout>}}_1}{\overset{{\mathrm{NUM}}_1-1}{\mathrm{\&Sigma;}}}\underset{j=0}{\overset{\mathrm{num}\_{\mathrm{ref}}_1-1}{\mathrm{\&Sigma;}}}{\mathrm{unify}}_1(i-j)\&CenterDot;{\mathrm{ref}}_1(\mathrm{num}\_{\mathrm{ref}}_1-j)$

Wherein, match ₁(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₁=N * M ₁, M ₁The symbol numbers of 1/3rd lead code wave sequence in the expression dPMR standard frame.

In the present embodiment, frame swynchronization code lock unit 130 carries out normalization filtering according to the amplitude of the baseband signal waveform of following formula after to sample quantization:

unify ₂(i)＝sample(i)×α ₂;0≤i＜num_ref ₂

α ₂＝max(|ref ₂(i)|)/max(|sample(i)|);0≤i＜num_ref ₂

Wherein, unify ₂(i) the sample quantization value of the filtered baseband signal waveform of expression normalization, the sample quantization value of the baseband signal of sample (i) expression described sample quantization unit (110) output, α ₂The normalization coefficient of expression frame swynchronization code, ref ₂(i) be the value of symbol of frame swynchronization code waveform in the dPMR standard frame, max (| ref ₂(i) |) be the amplitude maximum of frame swynchronization code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num_ref ₂Symbol numbers for frame swynchronization code waveform in the dPMR standard frame.

In the present embodiment, frame swynchronization code lock unit 130 carries out matched filtering according to following formula to the baseband signal waveform after normalization:

${\mathrm{match}}_2\left(i\right)=\underset{i=\mathrm{num}\_{\mathrm{<figure-callout\; id="2"\; label="ref"\; filenames="HDA00001985451400021.png,HDA00001985451400031.png"\; state="\{\{state\}\}">ref</figure-callout>}}_2}{\overset{{\mathrm{NUM}}_2-1}{\mathrm{\&Sigma;}}}\underset{j=0}{\overset{\mathrm{num}\_{\mathrm{ref}}_2-1}{\mathrm{\&Sigma;}}}{\mathrm{unify}}_2(i-j)\&CenterDot;{\mathrm{ref}}_2(\mathrm{num}\_{\mathrm{ref}}_2-j)$

Wherein, match ₂(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₂=N * M ₂, M ₂The symbol numbers of the frame swynchronization code wave sequence in the expression dPMR standard frame.

In the present embodiment, the phase place with maximum amplitude (optimum sampling determination point) that frame swynchronization code lock unit 130 obtains and the position corresponding relation for the treatment of frame swynchronization code waveform in the synchronous baseband signal waveform are as shown in figure 13, the present invention can locate the position for the treatment of frame swynchronization code waveform in the synchronous baseband signal waveform accurately, thereby realizes symbol synchronization in communication process.

In symbol synchronization method the second embodiment of the present invention, described step S3 may further comprise the steps:

S31, lead code normalization filter unit 121 carry out normalization filtering according to the amplitude of the amplitude of the lead code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of sample quantization unit 110 outputs;

S32, lead code matched filtering unit 122 receive through the filtered baseband signal waveform of normalization, the lead code waveform of choosing 1/3rd in the dPMR standard frame carries out three matched filterings to the filtered baseband signal waveform of described normalization, and has the phase place of maximum amplitude in the baseband signal waveform that output searches after each matched filtering;

S33, judging unit 123 receive three phase places of lead code matched filtering unit 122 outputs and judge whether described three phase places equate, if equate then execution in step S34, unequal then execution in step S31;

S34, judging unit 123 are exported sample quantization unit 110 to adjust the sampling determination points of sample quantization unit 110 with the phase place of maximum amplitude in the baseband signal waveform.

Described step S5 comprises step:

S51, frame swynchronization code normalization filter unit 131 carry out normalization filtering according to the amplitude of the amplitude of the frame swynchronization code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of described sample quantization unit 110 outputs;

S52, frame swynchronization code matched filtering unit 132 receive through the filtered baseband signal waveform of normalization, according to the frame swynchronization code waveform in the dPMR standard frame the filtered baseband signal waveform of described normalization is carried out matched filtering, and obtain the phase place that has maximum amplitude in the baseband signal waveform, the described phase place of obtaining is exported described sample quantization unit 110 to adjust the sampling determination point of described sample quantization unit 110.

In the present embodiment, consider that preamble sequence is long, 72bits is arranged, and each crest value of lead code waveform identical (referring to Fig. 3), therefore, in step S32, choose the lead code waveform of 1/3rd in the dPMR standard frame, be 24bits in the lead code waveform as the reference waveform, to the filtered baseband signal waveform of normalization carry out front in rear 3 matched filterings.

In the present embodiment, all the other situations are identical with symbol synchronization method the first embodiment of the present invention, do not repeat them here.

The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., all should be included within the claim scope of the present invention.

Claims (10)

1. a symbol synchronization device is characterized in that, comprising:

Sample quantization unit (110) carries out sample quantization according to local reference clock to baseband signal waveform, and the sample quantization value of output baseband signal waveform;

Lead code lock unit (120), carry out normalization and matched filtering according to the baseband signal waveform of the lead code waveform in the dPMR standard frame after to sample quantization, and obtain the phase place of maximum amplitude in the baseband signal waveform after normalization and matched filtering, the phase place of the maximum amplitude that obtains is exported described sample quantization unit (110) to adjust the sampling determination point of described sample quantization unit (110);

Frame swynchronization code lock unit (130), carry out normalization and matched filtering according to the baseband signal waveform of the frame swynchronization code waveform in the dPMR standard frame after to sample quantization, and obtain the phase place of maximum amplitude in the baseband signal waveform after normalization and matched filtering, the phase place of the maximum amplitude that obtains is exported described sample quantization unit (110) to adjust the sampling determination point of described sample quantization unit (110);

Timer (140), when beginning communication enables described lead code lock unit (120) until it stops to enable after exporting the phase place of maximum amplitude in its baseband signal waveform of obtaining, and enable described frame swynchronization code lock unit (130) until it stops to enable after exporting the phase place of maximum amplitude in its baseband signal waveform of obtaining through 60 milliseconds, and whenever again enable described frame swynchronization code lock unit (130) until it stops to enable after exporting the phase place of maximum amplitude in its baseband signal waveform of obtaining through 120 milliseconds.

2. symbol synchronization device according to claim 1 is characterized in that, described lead code lock unit (120) comprising:

Lead code normalization filter unit (121) carries out normalization filtering according to the amplitude of the amplitude of the lead code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of described sample quantization unit (110) output;

Lead code matched filtering unit (122), receive through the filtered baseband signal waveform of normalization, the lead code waveform of choosing 1/3rd in the dPMR standard frame carries out three matched filterings to the filtered baseband signal waveform of described normalization, and exports the phase place of maximum amplitude in the baseband signal waveform that searches after each matched filtering;

Judging unit (123), receive three phase places of described lead code matched filtering unit (122) output and judge whether described three phase places equate, if equal then this phase place is exported described sample quantization unit (110) to adjust the sampling determination point of described sample quantization unit (110), if unequal described three phase places that receive that then abandon.

3. symbol synchronization device according to claim 2 is characterized in that, described lead code normalization filter unit (121) carries out normalization filtering according to the amplitude of the baseband signal waveform of following formula after to sample quantization:

unify ₁(i)＝sample(i)×α ₁;0≤i＜num_ref ₁

α ₁＝max(|ref ₁(i)|)/max(|sample(i)|);0≤i＜num_ref ₁

Wherein, unify ₁(i) the sample quantization value of the filtered baseband signal waveform of expression normalization, the sample quantization value of the baseband signal of sample (i) expression sample quantization unit 110 outputs, α ₁The normalization coefficient of expression lead code, ref ₁(i) be the value of symbol of lead code waveform in the dPMR standard frame, max (| ref ₁(i) |) be the amplitude maximum of lead code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num_ref ₁Symbol numbers for lead code waveform in the dPMR standard frame;

Described lead code matched filtering unit (122) carries out matched filtering according to following formula to the baseband signal waveform after normalization:

Wherein, match ₁(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₁=N * M ₁, M ₁The symbol numbers of 1/3rd lead code wave sequence in the expression dPMR standard frame, N is the symbol numbers of each symbol clock in the cycle of sampling to baseband signal waveform in described sample quantization unit (110).

4. symbol synchronization device according to claim 1 is characterized in that, described frame swynchronization code lock unit (130) comprising:

Frame swynchronization code normalization filter unit (131) carries out normalization filtering according to the amplitude of the amplitude of the frame swynchronization code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of described sample quantization unit (110) output;

Frame swynchronization code matched filtering unit (132), receive through the filtered baseband signal waveform of normalization, according to the frame swynchronization code waveform in the dPMR standard frame the filtered baseband signal waveform of described normalization is carried out matched filtering, and obtain the phase place of maximum amplitude in the baseband signal waveform, the described phase place of obtaining is exported described sample quantization unit (110) to adjust the sampling determination point of described sample quantization unit (110).

5. symbol synchronization device according to claim 4 is characterized in that, described frame swynchronization code normalization filter unit (131) carries out normalization filtering according to the amplitude of the baseband signal waveform of following formula after to sample quantization:

unify ₂(i)＝sample(i)×α ₂;0≤i＜num_ref ₂

α ₂＝max(|ref ₂(i)|)/max(|sample(i)|);0≤i＜num_ref ₂

Wherein, unify ₂(i) the sample quantization value of the filtered baseband signal waveform of expression normalization, the sample quantization value of the baseband signal of sample (i) expression described sample quantization unit (110) output, α ₂The normalization coefficient of expression frame swynchronization code, ref ₂(i) be the value of symbol of frame swynchronization code waveform in the dPMR standard frame, max (| ref ₂(i) |) be the amplitude maximum of frame swynchronization code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num_ref ₂Symbol numbers for frame swynchronization code waveform in the dPMR standard frame;

Described frame swynchronization code matched filtering unit (132) carries out matched filtering according to following formula to the baseband signal waveform after normalization:

Wherein, match ₂(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₂=N * M ₂, M ₂The symbol numbers of the frame swynchronization code wave sequence in the expression dPMR standard frame, N is the symbol numbers of each symbol clock in the cycle of sampling to baseband signal waveform in described sample quantization unit (110).

6. a symbol synchronization method is characterized in that, may further comprise the steps:

S1, sample quantization unit (110) are carried out sample quantization according to local reference clock to baseband signal waveform;

S2, timer (140) enable lead code lock unit (120);

S3, described lead code lock unit (120) carry out normalization and matched filtering according to the baseband signal waveform of the lead code waveform in the dPMR standard frame after to sample quantization, and obtain the phase place of maximum amplitude in the baseband signal waveform after normalization and matched filtering, the phase place of the maximum amplitude that obtains is exported described sample quantization unit (110) to adjust the sampling determination point of described sample quantization unit (110);

S4, described timer (140) stop to enable described lead code lock unit (120), and enable frame swynchronization code lock unit (130) through 60 milliseconds;

S5, described frame swynchronization code lock unit (130) carry out normalization and matched filtering according to the baseband signal waveform of the frame swynchronization code waveform in the dPMR standard frame after to sample quantization, and obtain the phase place of maximum amplitude in the baseband signal waveform after normalization and matched filtering, the phase place of the maximum amplitude that obtains is exported described sample quantization unit (110) to adjust the sampling determination point of described sample quantization unit (110);

S6, described timer (140) stop to enable described frame swynchronization code lock unit (130), and again enable described frame swynchronization code lock unit (130), execution in step S5 through 120 milliseconds.

7. symbol synchronization method according to claim 6, it is characterized in that, described lead code lock unit (120) comprises lead code normalization filter unit (121), lead code matched filtering unit (122) and judging unit (123), and described step S3 may further comprise the steps:

S31, described lead code normalization filter unit (121) carry out normalization filtering according to the amplitude of the amplitude of the lead code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of described sample quantization unit (110) output;

S32, described lead code matched filtering unit (122) receive through the filtered baseband signal waveform of normalization, the lead code waveform of choosing 1/3rd in the dPMR standard frame carries out three matched filterings to the filtered baseband signal waveform of described normalization, and exports the phase place of maximum amplitude in the baseband signal waveform that searches after each matched filtering;

S33, described judging unit (123) receive three phase places of described lead code matched filtering unit (122) output and judge whether described three phase places equate, if equate then execution in step S34, unequal then execution in step S31;

S34, described judging unit (123) are exported described sample quantization unit (110) to adjust the sampling determination point of described sample quantization unit (110) with the phase place of maximum amplitude in the baseband signal waveform.

8. symbol synchronization method according to claim 7 is characterized in that, described lead code normalization filter unit (121) carries out normalization filtering according to the amplitude of the baseband signal waveform of following formula after to sample quantization:

unify ₁(i)＝sample(i)×α ₁;0＜i＜num_ref ₁

α ₁＝max(|ref ₁(i)|)/max(|sample(i)|);0≤i＜num_ref ₁

Wherein, unify ₁(i) the sample quantization value of the filtered baseband signal waveform of expression normalization, the sample quantization value of the baseband signal of sample (i) expression sample quantization unit 110 outputs, α ₁The normalization coefficient of expression lead code, ref ₁(i) be the value of symbol of lead code waveform in the dPMR standard frame, max (| ref ₁(i) |) be the amplitude maximum of lead code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num_ref ₁Symbol numbers for lead code waveform in the dPMR standard frame;

Described lead code matched filtering unit (122) carries out matched filtering according to following formula to the baseband signal waveform after normalization:

Wherein, match ₁(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₁=N * M ₁, M ₁The symbol numbers of 1/3rd lead code wave sequence in the expression dPMR standard frame, N is the symbol numbers of each symbol clock in the cycle of sampling to baseband signal waveform in described sample quantization unit (110).

9. symbol synchronization method according to claim 6 is characterized in that, described frame swynchronization code lock unit (130) comprises frame swynchronization code normalization filter unit (131) and frame swynchronization code matched filtering unit (132), and described step S5 comprises step:

S51, described frame swynchronization code normalization filter unit (131) carry out normalization filtering according to the amplitude of the amplitude of the frame swynchronization code waveform in the dPMR standard frame baseband signal waveform after to the sample quantization of described sample quantization unit (110) output;

S52, described frame swynchronization code matched filtering unit (132) receive through the filtered baseband signal waveform of normalization, according to the frame swynchronization code waveform in the dPMR standard frame the filtered baseband signal waveform of described normalization is carried out matched filtering, and obtain the phase place of maximum amplitude in the baseband signal waveform, the described phase place of obtaining is exported described sample quantization unit (110) to adjust the sampling determination point of described sample quantization unit (110).

10. symbol synchronization device according to claim 9 is characterized in that, described frame swynchronization code normalization filter unit (131) carries out normalization filtering according to the amplitude of the baseband signal waveform of following formula after to sample quantization:

unify ₂(i)＝sample(i)×α ₂;0≤i＜num_ref ₂

α ₂＝max(|ref ₂(i)|)/max(|sample(i)|);0≤i＜num_ref ₂

Wherein, unify ₂(i) the sample quantization value of the filtered baseband signal waveform of expression normalization, the sample quantization value of the baseband signal of sample (i) expression described sample quantization unit (110) output, α ₂The normalization coefficient of expression frame swynchronization code, ref ₂(i) be the value of symbol of frame swynchronization code waveform in the dPMR standard frame, max (| ref ₂(i) |) be the amplitude maximum of frame swynchronization code waveform in the dPMR standard frame, max (| sample (i) |) be the amplitude maximum of the baseband signal waveform of sample quantization unit 110 sample quantizations, num_ref ₂Symbol numbers for frame swynchronization code waveform in the dPMR standard frame;

Described frame swynchronization code matched filtering unit (132) carries out matched filtering according to following formula to the baseband signal waveform after normalization:

Wherein, match ₂(i) be the sample quantization value of the baseband signal waveform after normalization and matched filtering, NUM ₂=N * M ₂, M ₂The symbol numbers of the frame swynchronization code wave sequence in the expression dPMR standard frame, N is the symbol numbers of each symbol clock in the cycle of sampling to baseband signal waveform in described sample quantization unit (110).

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